低品位硫化铜矿的细菌浸出

以宁夏某低品位硫化铜矿为研究对象,利用嗜酸氧化亚铁硫杆菌(Acidithiobacillusferrooxidans)和嗜酸氧化硫硫杆菌(Acidithiobacillusthiooxidans)的混合菌,采用摇瓶浸出、小型柱浸和大型柱浸对矿石可浸性进行研究;采用X射线衍射仪分析矿物及其浸渣的成分;采用扫描电镜分析浸渣表面形貌及其表面元素的含量.结果表明摇瓶矿浆浓度为5%,浸出55d铜浸出率为94.38%;小型柱浸处理矿石2.10kg,矿石粒度小于15mm,浸出226d铜浸出率为62.50%;大型柱浸处理矿石77.85kg,矿石粒度小于25mm,浸出285d铜浸出率为50.63%.柱浸过程中,铜的浸出速率逐渐下降;浸渣中钙含量基本不变,而元素硫的含量明显增加,且存在新的石膏相;浸出后矿石表面元素硫、钙、铁的含量明显增加,在浸出过程中生成的硫酸钙结晶覆盖在矿石表面,铁在矿石表面形成沉淀,使矿石的渗透性变差,导致铜的浸出率逐渐下降.     

Bioleaching of chalcopyrite by pure and mixed culture

The bioleaching of chalcopyrite in shake flasks was investigated by using pure Acidithiobacillusferrooxidans and mixed culture isolated from the acid mine drainage in Yushui and Dabaoshan Copper Mine in China, marked as YS and DB, respectively. The mixed culture consisted mainly of Acidithiobacillus fOrrooxidans, Acidithiobacillus thiooxidans, and Leptospirillum spp. （Leptospirillum ferriphilum and Leptospirillum ferrooxians）. The results show that the mixed culture is more efficient than the pure Acidithiobacillus ferrooxidans because of the presence of the sulfur-oxidizing cultures that positively increase the dissolution rate and the recovery of copper from chalcopyrite. The pH value decreases with the decrease of chalcopyrite leaching rate, because of the formation ofjarosite as a passivation layer on the mineral surface during bioleaching. In the bioleaching using the mixed culture, low pH is got from the sulfur oxidizing inhibiting, the formation ofjarosite. The copper extraction reaches 46.27% in mixed culture and 30.37% in pure Acidithiobacillusferrooxidans after leaching for 75 d.     

某难选钒钛磁铁矿选矿试验

为开发利用某钒钛磁铁矿资源,通过采集具有代表性的矿样,在矿石性质研究的基础上进行了选矿试验研究。试验结果表明:当磨矿细度为-0.074 mm 51.35%时,采用湿式弱磁筒式磁选机进行1粗1精磁选流程试验,可获得产率为24.15%,铁品位为68.73%,铁回收率为36.02%的铁精矿,实现了钛磁铁矿的有效富集和回收;针对选铁尾矿采用单一强磁、脱泥—磁化焙烧—弱磁—强磁、强磁—直接还原—弱磁工艺很难获得TiO_2含量大于47%的钛铁精矿,要实现钒钛磁铁矿资源的综合利用,仍需要先进的冶炼工艺的研发。     

高砷原生硫化铜矿细菌浸出试验研究

采用中温嗜酸氧化亚铁硫杆菌、喜温嗜酸硫杆菌和高温Ferroplasma属古菌对高砷原生硫化铜矿进行了细菌浸出试验研究。研究结果表明, 喜温嗜酸硫杆菌对高砷原生硫化铜矿的浸出效果比中温嗜酸氧化亚铁硫杆菌好。中温菌对砷的耐受性比高温菌高。在高温菌浸出过程中, 铜优先于砷溶解, 砷主要留在浸渣中; 细菌接种量对高砷原生硫化铜矿的浸出有一定的影响, 接种量为10%时浸出效果最好。提高温度有利于初始阶段铜的浸出, 随着浸出的进行, 温度的影响逐渐降低, 细菌作用占主导作用。驯化高砷耐受能力的高温菌将成为进一步的研究目标。     

某铁精矿提纯工艺试验研究

针对某地TFe=66. 81%、Si O2=5. 92%的普通铁精粉进行了超纯铁精矿提纯试验研究,原料经过弱磁抛尾、阶段磨矿和阶段磁选提纯后,获得了TFe=70. 91%、Si O2=0. 73%、盐酸不溶物为0. 89%的磁选精矿。磁选精矿经反浮选深度提纯,获得TFe=71. 78%、Si O2=0. 21%、盐酸不溶物为0. 24%的超纯铁精矿;同时,获得产率41. 07%,TFe为69. 75%的普通铁精矿。试验证明,普通铁精粉抛尾-磁选-反浮选的总回收率高,综合经济效益显著。     

Bacterial leaching of chalcopyrite and bornite with native bioleaching microorganism

A native mesophilic iron-oxidizing bacterium, Acidithiobacillus ferrooxidans, has been isolated （30 ℃） from a typical, lead-zinc concentrate of Dachang Mine in the region of Liuzhou located in the southwest of China. Two typical copper sulfide minerals, chalcopyrite and bornite, were from Meizhou Copper Mine in the region of Guangdong Province, China. Variation of pH and cell growth on time and effects of some factors such as temperature, inoculation cell number, and pulp density on the bioleaching of chalcopyrite and bornite were investigated. The results obtained from the bioleaching experiments indicate that the efficiency of copper extraction depends on all of the mentioned variables, especially the pulp density has more effect than the other factors on the microorganism. In addition, the results show that the maximum copper recovery was achieved using a mesophilic culture. The copper dissolution reached 51.34% for the chalcopyrite while it was 72.35% for the bornite at pH 2.0, initial Fe（ Ⅱ ） concentration 9 g/L and pulp density 5%, after 30 d.     

蒙自多金属硫化矿砷硫分离技术研究

针对蒙自多金属硫化矿特点, 采用“砷硫混浮-砷硫分离”的工艺流程, 选择高效低毒药剂丙基黄原酸钠作砷抑制剂进行了砷硫分离, 最终获得硫品位43.05%、含砷0.51%的硫精矿, 硫回收率79.53%。